The invention generally relates to robotics, and relates in particular to robotic control systems that are designed to accommodate a wide variety of unexpected conditions and loads.
Most industrial robotic systems operate in a top-down manner, generally as follows: a controller samples a variety of sensors, and then logic on that same controller computes whether or not to take action. The benefit of this logic flow (usually referred to as “polling”) is that all of the control logic is in the same place. The disadvantage is that in practical robotic systems, the signals are often sampled quite slowly. Also, all sensors must be wired to the control cabinet leading to long and error-prone cable runs.
A specific example of this traditional architecture would generally be implemented by a legacy robot supplier such as those sold by ABB Robotics, Inc. of Auburn Hills, Mich., Kuka Roboter GmbH of Germany, Fanuc America Corporation of Rochester Hills, Mich., or one of their top-tier integrators. All of these suppliers generally encourage the same architecture, and have similar form factors. For example: a welding cell used in an automotive facility might have an ABB IRC5 control cabinet, an ABB IRB2600 1.85 m reach 6 degree of freedom robot, a Miller GMAW welding unit wired over an industrial bus (Devicenet/CANbus) to the IRC5, and an endo-farm tooling package mounting a GMAW torch (e.g., a Tregaskiss Tough Gun). All programming is done on the IRC5, and the end effector has no knowledge of the world, and things like crashes can only be observed or prevented on the IRC5, which is itself quite limited.
Again, in such systems, however, the signals are often sampled relatively slowly and sensors must generally be wired to the control cabinet. There remains a need therefore, for a robotic control system that is able to efficiently and reliably provide dynamic control and responsiveness to conditions in the environment of the robot.